Note: Descriptions are shown in the official language in which they were submitted.
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SYSTEM AND METHOD FOR ESTABLISHING COMMUNICATIONS OVER A
NETWORK
Technical Field
This invention relates to communications systems,
and more particularly to establishing communications with a
mobile party using paging technology.
Background of the Invention
Establishing communications with a called party
becomes a problem when that party is mobile. In general,
persons wishing to contact a particular party initiate a
call to a specific telephone associated with that party,
such as the party's home telephone. A disadvantage of this
method of communication is that parties are not always in
close proximity to their home telephone, or for that matter,
in close proximity to any telephone. This presents a problem
to persons who need to contact the mobile party immediately,
and regardless of that party's location.
Several technologies have developed in an effort
to solve the problem of establishing communication with a
mobile party. These include call forwarding, paging, and
cellular systems. However, each of these technologies has
drawbacks which prevent seamless and ubiquitous
communication.
Call forwarding is a well-known technique whereby
an individual who plans to be away from an associated
telephone can redirect calls to an alternate telephone. For
example, an office worker planning to go on vacation could
redirect calls to an office mate's telephone. Such a
system, although desirable, is inflexible. It requires that
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the forwarding party access a telephone to activate and
deactivate the call forwarding, and to change the forwarding
number. This inflexibility is particularly harsh on those
parties that require frequent changes to their forwarding
number, such as a travelling salesman who is on the road and
would like to receive calls from potential buyers.
Moreover, present call forwarding schemes make
inefficient use of network resources. Calls must be sent to
the forwarding party's end office before they are ,
redirected. Thus, for example, when a party forwards calls
from the party's home telephone in California to a
relative's telephone in New Jersey, calls from New York to
the party's home telephone will be routed to California
before being forwarded to New York. Such a process
unnecessarily ties up network resources from New York to
California to complete a call from New York to New Jersey.
In a paging system, a mobile individual carries a
portable pager. Typically, the pager is assigned a telephone
number and is capable of receiving a predetermined radio
signal. When a caller dials the pager's number the
predetermined radio signal is broadcast and the pager
responds to the signal by activating an audible and/or
visual alarm. The alarm serves to alert the mobile
individual that an attempt to contact her has been made.
Often, the caller's telephone number will be included in the
radio signal so that the pager can record the caller's
number and the called party can initiate a return call at
some later time. One of the drawbacks of past paging systems
is that they do not usually support two-way communication.
Thus, in a typical paging scenario, the called party must
relocate and initiate a return call to establish full two-
way communication with the calling party. Such relocation
may be inconvenient and untimely resulting in "telephone
tag" - situations in which two individuals periodically try
to contact one another and fail because the other person is
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unavailable.
Another drawback of past paging systems is the
delay associated with the paging queue. In general, a paging
service can only transmit one page at a time . However, a
service usually receives many paging requests at once.
Consequently, a queue builds up at the service's broadcast
facility and a delay in paging throughput times results.
This problem is compounded in paging services that offer
national coverage to their subscribers. In such services a
subscriber's pages are broadcast from several facilities,
and therefore a delay in throughput times results at each
facility.
Cellular systems offer an answer to the relocation
problems present in call forwarding systems and paging
systems but introduce a host of new problems. A typical
cellular phone is a wireless two-way voice communication
device that can be carried on an individual's person.
Typically, each cellular phone user subscribes to service
with a carrier in a particular geographic region served by
that carrier. Calls to the subscriber, when the subscriber
is in the home region, are easily completed since such calls
are routed through a Mobile Telephone Switching Office
(MTSO) serving the home region. However, when a subscriber
is located in a different region, the subscriber is
designated a "roamer", and call completion becomes more
difficult because it is not known, a priori, through which
MTSO to route the call.
The roamer problem may be overcome by having the
roaming subscriber notify the "home MTSO" that she will be
located in another region. This allows the necessary
information to be transmitted from the "home MTSO" to the
"host MTSO" so that the "host MTSO" can route the
subscriber's calls. This "cellular call forwarding",
however, introduces problems similar to those associated
with traditional call forwarding. Moreover, a11 cellular
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communications - including those within the home region -
suffer from a sensitivity to noise, precluding guaranteed high
quality communications.
Given the problems associated with the prior call
forwarding, paging, and cellular systems, there is a need to
provide a system that will assure ubiquitous high quality
communications with mobile parties.
The invention disclosed in the M.J. Foladare 2-13-13-17
application, cited hereinabove, addresses the foregoing
disadvantages in prior systems used to communicate with mobile
individuals. The Foladare 2-13-13-17 invention disclosed a
system for communicating with a mobile individual wherein the
mobile individual uses a two-way pager to transmit a
forwarding number on a call by call basis. In this manner,
the invention overcame the disadvantages of the prior systems
.
However, the Foladare 2-13-13-17 invention possesses a
characteristic that can be improved upon, namely, the lengthy
call setup time that results from having to wait for the
mobile party to transmit the forwarding number.
Summary of the Invention
The present invention employs a two-way paging technique
to overcome the disadvantages present in the prior systems
used to communicate with mobile individuals, while minimizing
the time required to establish such communication.
In accordance with one aspect of the present invention
there is provided a communications system for completing a
call initiated at a caller communication device and directed
to a personal telephone number of a subscriber, the subscriber
being equipped with a two-way pager, the system comprising:
a) a paging system for receiving an update signal transmitted
by the subscriber through the two-way pager, the update signal
including a forwarding number to which the call will be
forwarded, the paging system including, a transceiver for
receiving the update signal from the pager and for
transmitting the update signal, a satellite for receiving the
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update signal transmitted from the transceiver and for
broadcasting the update signal, and a satellite station for
receiving the update signal broadcast from the satellite;b )
a customer routing point for receiving the update signal from
the paging system and extracting said forwarding number from
said update signal and store said forwarding number; c) a
network control point for retrieving said forwarding number
from said customer routing point based on the personal
telephone number and for using said forwarding number to
reroute the call to a called party communication device; d)
means for coupling the caller communication device to said
network control point; e) means for coupling said network
control point to said customer routing point; and f ) means for
coupling the caller communication device to said called party
communication device.
In accordance with another aspect of the present
invention there is provided a method of completing a call
initiated at a caller communication device and directed to a
personal telephone number of a subscriber, the subscriber
being equipped with a two-way pager, the method comprising the
steps of: a) transmitting an update signal from the two-way
pager to a paging system transceiver, the update signal
including a forwarding number for the subscriber; b)
transmitting the update signal from the transceiver to a
paging system satellite; c) broadcasting the update signal
from the paging system satellite for reception by a paging
system satellite station; d) transmitting the forwarding
signal broadcast from the paging system satellite station to
a customer routing point; e) coupling the call initiated at
the caller communication device to a network control point;
f ) using said network control point to retrieve the forwarding
number from a customer routing point based on the personal
telephone number; and g) routing the call to a called party
communication device associated with said forwarding number.
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In accordance with yet another aspect of the present
invention there is provided a communication system for
completing a call initiated at a caller communication device
and directed to a personal telephone number of a subscriber,
the subscriber being equipped with a two-way pager, the system
comprising: a) a paging system for receiving an update signal
transmitted by the subscriber through the two-way pager, the
update signal including a forwarding number to which the call
will be forwarded, the paging system including, a transceiver
for receiving the update signal from the pager and for
transmitting the update signal, a satellite for receiving the
update signal transmitted from the transceiver and for
broadcasting the update signal, and a satellite station for
receiving the update signal broadcast from the satellite; b)
a customer routing point for receiving the update signal from
the satellite station, the customer routing point extracting
said forwarding number from said update signal and store said
forwarding number; and c) an adjunct for receiving the call
from the caller communication device, retrieving said
forwarding number from said customer routing point, and
forwarding the call to a called party communication device
associated with said forwarding number.
A mobile person who wishes to take advantage of the
present invention is equipped with a two-way pager and is
assigned a Personal Telephone Number (PTN). The mobile person
uses the pager to transmit a forwarding telephone number to
a paging service. The paging service relays the forwarding
number to a Customer Routing Point (CRP) where the number is
stored. Thereafter, whenever a call is placed to the
mobile person's PTN, the terminating number is
retrieved from the CRP and is used to forward the call to a
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terminating telephone.
In a preferred embodiment of the invention, a call
to a mobile person would be completed according to the
following "registration" procedure. The mobile person is
equipped with a two-way pager having a keypad which the
person uses to "key in" a forwarding telephone number, the
forwarding number being associated with a terminating
telephone to which the person's calls are to be forwarded.
The person then initiates transmission of an update signal
from the two-way pager to a paging service transceiver.
Included within the update signal is the forwarding number.
After receiving the update signal, the paging
service transceiver relays the signal to a satellite ground
station, either directly, or through a satellite. The ground
station, in turn, relays the signal to the CRP where the
forwarding number is extracted from the signal and stored
for retrieval at a later time. At this point the system is
configured to forward the mobile person's incoming calls.
A caller initiates an incoming call from a caller
telephone to the mobile person by dialing the mobile
person's PTN. The call is routed to a network access switch
which is coupled to a Network Control Point (NCP). The NCP
uses the dialed PTN to access the CRP and retrieve the
mobile person's forwarding number. The NCP then passes the
forwarding number to the network access switch which uses
the number to reroute the call to a terminating telephone.
The mobile person may then "pick up" the call at the
terminating telephone.
The present invention offers several advantages
over the prior systems. First, the mobile party can change
the forwarding number using the two-way pager, eliminating
the need to access a telephone each time the party wishes to
change the forwarding number. Second, the mobile party may
change the forwarding number on a call by call basis,
determining the identification of a caller from the caller
- 6 -
identification number and forwarding the caller accordingly.
Third, unlike traditional paging systems, the mobile party
does not need to relocate and initiate a return call. Thus,
the calling party is not burdened with waiting for a return
call and "telephone tag" situations are avoided. Fourth, the
invention allows a mobile party to redirect calls to a
cellular unit, thereby, providing a way for the mobile party
to take advantage of cellular service when it is available
while at the same time providing alternate communication ,
when it is not available.
Moreover, the present invention allows call
forwarding to be implemented at a point that is in close
proximity to the originating telephone (typically near the
first network switch). Thereby, allowing more efficient
routing of forwarded calls and avoiding unnecessary use of
network resources.
The present invention also offers advantages over
the invention of commonly assigned pending patent
application entitled SYSTEM AND METHOD FOR ESTABLISHING
COMMUNICATIONS WITH A MOBILE PARTY (M.J. Foladare 2-13-13-
17), filed on the same date hereof. In that invention the
mobile party used a two-way pager to respond to calls on a
"call by call" basis. By contrast, the present invention
allows the mobile party to "register" a forwarding number so
that the party may still change the forwarding number
wherever and whenever the party wants, but does not need
respond on a call by call basis. Furthermore, registration
allows for shorter call setup times since the system does
not need to wait for the subscriber to transmit a response
before implementing a forwarding procedure. Moreover, the
Foladare 2-13-13-17 invention required the bridging or
merging of two separate calls in order to complete one call,
a technique which places an added burden on system hardware
and also contributes to call setup times. The present
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invention reduces the hardware burden and the contribution
to call setup times by forwarding calls through rerouting
rather than bridging or merging. In addition, the
present invention may be combined with the Foladare 2-13-13-
17 invention in an embodiment that realizes the advantages
of both using the two-way pager to forward calls on a
"registration" basis and using the two-way pager to forward
calls on a "call by call" basis.
Brief Description of the DrawincLs ,
FIG. 1 is a block-schematic diagram of a
communications system in accordance with the present
invention.
FIG. 2 is a block-schematic diagram of a preferred
embodiment of a communication system incorporating the
present invention.
FIG. 3 shows a pager appropriate for use in
accordance with the present invention.
FIGs 4A and 4B make up a flow chart depicting the
procedure followed to update a subscriber's forwarding
number.
FIG. 5 is a flow chart depicting the procedure
followed to complete a call according to the present
invention.
FIG. 6 is a block-schematic diagram of a further
embodiment of a communication system in accordance with the
present invention.
FIG. 7 is a block-schematic diagram of a
communication system that may be used to implement call by
call mode forwarding.
FIG. 8 is a block-schematic diagram of an existing
telephone network incorporating the elements of FIG.
7. FIGS. 9A and 9B make up a flowchart
depicting the steps taken in forwarding calls on a call by
call basis.
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Detailed Descrig,tion
Referring to FIG. 1, there is shown a block
diagram of a communication system incorporating the present
invention. In accordance with the invention, a caller will
be able to complete a call to a mobile party who is equipped
with a two-way pager 10. The caller initiates the call via
a caller telephone 12. At this point it should be noted that
the caller telephone, like all other telephones hereinafter
discussed, is used merely as an illustration, and that the
I5 invention may be implemented using a variety of
communication devices, including, but not limited to
telephones, computers, and facsimile machines.
In any event, caller telephone 12 is coupled to a
network access switch 14 by a first communication coupling
16. First communication coupling 16, and all communication
couplings hereinafter described, may take the form of a
telephone line, twisted pair line, coaxial cable, fiber
optic line, wireless link, or any other type of
communication coupling.
Through first communication coupling 16, network
access switch 14, and a second communication coupling 22
caller telephone 12 is coupled to a Network Control Point
(NCP) 24. The NCP is coupled to a Customer Routing Point
(CRP) 34 via a third communication coupling 26, and the CRP
is, in turn, coupled to a paging service 28 via a fourth
communication coupling 27. The mobile party uses the pager
to transmit an update signal, represented by wireless link
30, to the paging service. The update signal includes a
forwarding telephone number that is associated with a
terminating telephone 32, and may include an identification
signal containing information sufficient for identifying the
transmitting pager. Upon receiving the update signal from
the pager, the paging service relays the signal to the CRP
where the forwarding number is extracted from the signal and
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stored. The forwarding number supplied by the mobile party
is cross-referenced with the party's PTN so that whenever
the party's PTN is dialed the terminating number for that
party may be retrieved from the CRP.
When a caller initiates a call by dialing the
l0 mobile party's PTN, the call is coupled to NCP 24 via the
combination of first communication coupling 16, network
access switch 14, and second communication coupling 22. The
NCP then queries the CRP through third communication
coupling 26. Based on the dialed PTN, the CRP retrieves the
mobile party's forwarding number and passes it back to the
NCP via the third communication coupling. The NCP, in turn,
passes the forwarding number to the network access switch 14 '
which uses the number to reroute the call to terminating
telephone 32. The network access switch 14 reroutes the call
20, to the terminating telephone via a fourth communication
coupling 20. At this point, the call may be "picked up" by
the mobile party at the terminating telephone.
It should be noted that the functions of CRP 34
may be incorporated into NCP 24 or paging service 28, in
which case the present invention may be implemented without
a separate CRP element.
In a preferred embodiment, as shown in FIG. 2, the
present invention is incorporated into an existing telephone
network. As shown in the figure, a caller 40 seeks to
establish communications with a mobile party, or
"subscriber", 76 who is assigned a Personal Telephone Number
(PTN) and is equipped with a two-way pager 77. The caller
initiates an incoming call from a telephone 41 by dialing
the subscriber's PTN. This incoming call is coupled to a
f first local of f ice 42 in the caller' s locality through a
first telephone line 54. The first local office routes the
call to an originating access switch 44 over a first trunk
line 56. Switch 44 may take the form of a digital switch, or
an electronic switching system, such as an AT&T 4ESSTM switch
- 10 -
("4E" switch). For a more complete description of a 4E
switch see, The Bell System Technical Journal, Vol. 56, No.
7, pp 1015-1320, pub. Sept. 1977.
Once the call has been routed to switch 44, switch
44 queries a Network Control Point (NCP) 66 via a first
Common Channel Interoffice Signaling (CCIS) link 78. (CCIS
combines the signaling information for a number of channels
and transmits the information over a data link derived from
a dedicated facility). At this point, if the subscriber has
provisioned for the collection of Customer Entered Digits
(CED) the NCP instructs switch 44 to couple the call to a
Voice Response Unit (VRU) 43 via a first communication link
57. The VRU (e. g. an AT&T Network Services Complex, or NSCX)
then plays a standard prompting announcement to the caller
and collects the CED (e. g. a Personal Identification Number,
or PIN) via the reception of up to 10 Dual Tone Multi
Frequency (DTMF) digits (i.e. Touch ToneTM signals from a
Touch ToneTM telephone). In a system using a CED, provision
must be made for the case where a caller can not enter
digits because the caller is at a rotary dial station or
does not respond to the prompt. In these two situations, the
VRU may allow for a time-out or an abbreviated dialing
sequence (e. g., #) to denote that no digits are forthcoming.
Any CED collected by the VRU is passed back to the NCP.
After the collection of CED, or immediately after
the originating access switch queries the NCP, whatever the
case may be, the NCP queries a Customer Routing Point (CRP)
68 via a second CCIS link 67. In the query, the NCP sends
the CED, the PTN, and the caller telephone number (Automatic
Number Identification number, or "ANI"). Based on the ANI
and/or CED, the CRP screens the call, deciding whether or
not the call is to be routed directly to the subscriber. If
the call is not to be routed directly to the subscriber, the
CRP instructs the NCP to route the call to an alternate
treatment, such as a voice mailbox. If the call is to routed
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directly to the subscriber, the CRP accesses a subscriber
record stored within the CRP, retrieves a forwarding number
for the subscriber from the record, and returns the
forwarding number to the NCP via CCIS link 67. The NCP
relays the forwarding number to the originating access
switch via CCIS link 78 where the number is used to reroute
the incoming call.
The subscriber may update the forwarding number at
any time using the two-way pager. To update the forwarding
number subscriber 76 generates an update signal containing
the new forwarding number using two-way pager 77. The update
signal is transmitted to a paging service transceiver 74.
The transceiver relays the update signal to a satellite
ground station 70, either directly, via communication
coupling 85, or indirectly, via wireless link 86, satellite
72, and wireless link 84 via wireless link 86. The satellite
ground station, in turn, passes the signal to the CRP via a
second communication link 82. The CRP extracts the new
forwarding number and uses it to update the subscriber's CRP
record with the new forwarding number.
Calls are forwarded based on the most recent
update of the forwarding number. As described above,
whenever an incoming call passes screening by the CRP, NCP
66 retrieves the forwarding number from CRP 68 and passes it
to originating access switch 44 for use in rerouting the
call to a terminating telephone 92. Rerouting from the
originating access switch to the terminating telephone is
achieved through: a second trunk line 58, a terminating
access switch 60 (which, like switch 44, may be a digital
switch or a 4E switch), a third trunk line 62, a second
local office 64, and a second telephone line 90. The
originating access switch couples the call to the
terminating access switch over the second trunk line. The
terminating access switch, in turn, couples the call to the
second local office over the third trunk line. The second
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local office then couples the call to the terminating
telephone over the second telephone line. After rerouting is
complete the call may be "picked up" by the subscriber at
the terminating telephone.
FIG. 3 shows an illustrative embodiment of a two-
way pager 102, a transceiver 112, a satellite 114, a
satellite ground station 1l6, wireless links 111, 113 and
115, and a communication link 117, the embodiment being
suitable for use in accordance with the present invention. ,
The pager 100 includes: a display 102, such as a liquid
crystal display or light emitting diode display; a select
key 104; a menu key 106; a keypad l08; and a mode indicator
110, that may be included within the display l02. FIG. 3
will be referenced in the following discussion of the
flowchart in FIGs 4A and 4B.
FIGS. 4A and 4B show the steps taken in updating
the subscriber's forwarding number. The pager of FIG. 3 may
be used to update the forwarding number on a "registration"
basis, herein described, or on a "call by call" basis, as
described in cross-referenced application Foladare 2-13-13-
17. Thus, the description that follows includes provisions
for both "registration" and "call by call" updating.
The first step the subscriber takes to update the
forwarding number is to depress menu key l04 on pager 100
(step 202). The word "update" will appear in display 102.
The subscriber then depresses select key l06 to select
"update" (step 204). The word "update" will flash in the
display to indicate that the subscriber may enter the update
number (step 206). The subscriber may now input the
forwarding number via keypad 108 followed by the # key to
indicate the end of input (step 208) . To enter a special
call handling instruction (as described in Foladare 2-13-13-
17), such as a conference call instruction, a number
associated with that instruction would be input rather than
a forwarding number (step 208). A subscriber who does not
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want to change the forwarding number and does not want to
input a special instruction number may simply depress the #
key without keying in a number.
Moreover, in a preferred embodiment, the pager is
equipped with the ability to store forwarding numbers so
that abbreviated key sequences may be used to change the
forwarding number. For example, the subscriber's office
telephone number may be stored in the pager's memory at a
first location and the subscriber's home telephone number
may be stored in the pager's memory at a second location.
Thereafter, when the subscriber wants to change the
forwarding number to the office number, the subscriber
simply keys in a 1 followed by the # sign. Similarly, when
the subscriber wants to change the forwarding number to the
home number, the subscriber simply keys in a 2 followed by
the # sign.
In any case, after receiving a # input, the
pager's mode indicator will flash (step 210). At this point,
the subscriber must select the desired mode (step 212). The
pager determines if the desired mode is the current mode
(step 2l4 when desired mode is registration mode; step 222
when desired mode is call by call mode). If the subscriber
desires the registration mode and the current mode is not
the registration mode, then before the flashing mode
indicator goes steady, the subscriber depresses select key
l06 to change to registration mode (step 2l6). If the
subscriber desires the registration mode and the current
mode is the registration mode, the subscriber allows a
period of time to pass, after which the flashing mode
indicator will go steady; or, in the alternative, the
subscriber may depress the # key to curtail timing and
retain the current mode (step 218).
Similarly, if the subscriber desires the call by
call mode and the current mode is not the call by call mode,
then before the flashing mode indicator goes steady, the
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subscriber depresses select key 106 to change to call by
call mode (step 224). If the subscriber desires the call by
call mode and the current mode is the call by call mode, the
subscriber allows a period of time to pass, after which the
flashing mode indicator will go steady; or, in the
alternative, the subscriber may depress the # key to curtail
timing and retain the current mode (step 226) . After the
mode has been selected, the pager signals the transceiver
112 via wireless link 111, sending the pager code, updated
forwarding number, and a mode indicator (step 220 for
registration mode; step 228 for call by call mode).
Following reception of the pager's transmission,
the transceiver 112 relays the pager code, new forwarding
number, and mode indicator to the satellite ground station
l16 (step 230), either directly, over communication coupling
117, or indirectly, through satellite 114 and wireless links
l13 and l15. The next step (step 232) depends on the
selected mode. When the registration mode is selected, the
satellite station determines the subscriber's PTN from the
pager code, uses the PTN to retrieve the subscriber's
Customer Routing Point (CRP) record, and, finally, updates
the record to reflect the new mode and forwarding number.
When the call by call mode is selected, the satellite
station merely relays the updated forwarding number to an
adjunct (described in Foladare 2-13-13-17) where it is used
to forward an incoming call. The update is complete after
step 232 (step 234).
FIG. 5 shows, in flowchart form, the steps taken
in completing a call in accordance with the present
invention. In the following discussion of FIGs 5A and 5B
references will be made to FIG 2.
As shown in FIG. 5, a caller initiates a call by
dialing the subscriber's PTN (step 300). The call is routed
to the originating access switch (step 302) which queries
the NCP for routing information (step 304). At this point,
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if the subscriber has provisioned for the collection of a
CED, the NCP instructs the originating access switch to
connect the call to the VRU for collection of DTMF digits,
and to pass the collected digits back to the NCP (optional
step 306). After collection of the CED digits, or
immediately following step 304, whatever the case may be,
the NCP queries the CRP for the subscriber record, sending
the CRP the CED, PTN, and ANI (step 308). The CRP then
retrieves the subscriber's record based on the PTN (step
3l0). The record includes the forwarding number, and may
include instructions to screen the incoming call. If the
subscriber has provisioned the subscriber record to initiate
call screening, the CRP screens the incoming call
(determines the appropriate treatment for the call) based on
the CED and/or ANI (step 312).
Based on the screening performed in step 3l2, a
decision is made on whether or not to route the call
directly to the subscriber (step 314). If the call is not to
be routed directly to the subscriber, the CRP instructs the
NCP to route the call to an alternate treatment, such as a
network announcement, voice mailbox, or service platform
(step 316). If the call is to be routed directly to the
subscriber, the CRP returns the forwarding number, or
"Network Routing Number" to the NCP which then uses the
number to route the call to the terminating telephone where
it can be "picked up" by the subscriber (step 318).
Following the rerouting of the call, the processing of the
call is complete (step 320).
FIG. 6 is a block-schematic diagram of a further
embodiment of a communication system in accordance with the
present invention. FIG. 6 is identical to FIG. 2 with the
exception of additional elements: adjunct 73, switch 47,
communication couplings 45,49,71,75, and wireless link 87.
The system of FIG. 6 may be used to offer subscriber's all
of the features associated with both the registration mode
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of operation (described hereinabove), and the call by call
mode of operation (described hereinbelow).
Referring to FIG. 7, there is shown a block
diagram containing the major elements of a communication
system that may be used to implement call by call mode
forwarding. As shown in the figure, a caller initiates a
call from a caller telephone 12' to a mobile party who is
equipped with a two-way pager 10'. The caller telephone is
coupled to a first network switch 14' by a first
communication coupling 16'. The first network switch is, in
turn, coupled to a second network switch 18' by a second
communication coupling 20'. The second network switch is
coupled to an adjunct 24', via third communication couplings
22', and to a third network switch 26', via fourth
communication coupling 30'. Thus, there is a path between
the caller telephone and the adjunct, and a path between the
caller telephone and the third network switch.
Adjunct 24' is an intelligent component external
to the network and connected to the network in the same way
that a switch or telephone is connected. Examples of
adjuncts include the AT&T Voice Response Units (VRUs), such
as a Conversant, and the Summa Four. Two possible ways of
connecting the adjunct to a network are: via a Common
Channel Interoffice Signaling (CCIS) link, and via an
Integrated Services Digital Network (ISDN) communication
link. In an alternative embodiment, the adjunct is internal
to the network, in which case the functioning of the adjunct
remains the same but a connecting link is not required.
When a call is initiated by dialing the mobile
party's PTN it is coupled to adjunct 24' via couplings 16',
14' and 22', and switches 14' and 18'. The adjunct puts the
call on "hold" and, based on the mobile party's identity
(known through the PTN), retrieves the information necessary
to page~the mobile party . This information may be contained
in a database internal to the adjunct or it may be read from
'~16~~~~
- 17 -
an external data base (not shown). Adjunct 24' passes the
necessary paging information to a paging service 28' via a
fifth communication coupling 34'. The paging service then
broadcasts a paging activation signal and a caller
identification signal, both intended for reception by two-
way pager 10'.
Pager 10' is equipped with: an alarm that is
activated in response to the pager activation signal, a
display that is responsive to the caller identification ,
signal, and a keyboard for specifying a forwarding number or
a special instruction. A mobile party who is alerted to a
call may check the pager's display to identify the caller,
and then, based on the identity of the caller, decide how to
treat the call. One possible treatment is to forward the
call to a called party telephone 32'. The called party
telephone may be a nearby telephone station or some remote
telephone station, such as a secretary's station. To forward
the call to the called party telephone the mobile party keys
the telephone number of the called party telephone into the
pager using the pager's keyboard, and then transmits the
number to the paging service 28'. The paging service passes
the forwarding number to the adjunct where it is used to
forward the call.
Other possible call treatments include those that
may be used when the mobile party is busy. If the mobile
party is busy with a call when a subsequent call to the
party's PTN is placed, the party may forward the subsequent
call to an alternate number, put the previous caller on hold
and talk to the subsequent caller, or use the pager to
transmit a conference call instruction to talk to both
callers at the same time. Also, if the mobile party has
forwarded the subsequent call but becomes free before the
subsequent caller disconnects, the party may interrupt the
forwarding of the subsequent call and redirect the call to
the party.
21~~43~
-18-
In the configuration of FIG. 7, adjunct 24'
forwards the incoming call by holding the call at the
adjunct while launching a second call from the adjunct to
called party telephone 32'. This second call is routed
through: communication coupling 22', second network switch
18', communication coupling 30', third network switch 26',
and sixth communication coupling 36'. After the second call
is complete the adjunct bridges the incoming call and the
second call together so that the caller telephone is coupled
to the called party telephone through the adjunct. As an
alternative, the adjunct may merge the incoming call and the
second call at the second network switch, in which case the
adjunct drops from the call. Once the incoming call and the
second call have been bridged, or merged, into a "forwarded
call" the forwarded call may be "picked up" by the mobile
party at telephone 32'.
A similar procedure may be used to implement
special call handling instructions. For instance, in the
case of a conference call between two callers and the mobile
party, the adjunct may bridge, or merge the two incoming
calls from the callers to an outgoing call to the mobile
party.
FIG. 8, shows how call by call forwarding may be
implemented in an existing telephone network. As shown, a
caller 40' seeks to establish communications with a mobile
party, or "subscriber", 76' who is equipped with a two-way
pager 77'. The subscriber is assigned a Personal Telephone
Number (PTN). The caller initiates an incoming call from a
telephone 41' by dialing the mobile party's PTN. This
incoming call is coupled to a local office 42' in the
caller's locality through a telephone line 54'. The local
office 42' routes the call to an originating access switch
44' over a trunk line 56'. Switch 44' may take the form of
a digital switch, or an electronic switching system, such as
an AT&T "4E" switch.
- 19 -
S Once the call has been routed to switch 44' , a
Network Control Point (NCP) 66' receives the call's
signaling information, including the dialed PTN, over a CCIS
link 78'. The NCP uses the dialed number to retrieve routing
information from the NCP's associated database. The NCP then
routes the call over a trunk line 58' to a terminating
access switch 46', which, like the originating access
switch, may be a digital switch or a 4E switch. Switch 46'
is connectable to an adjunct 68' via an ISDN link 80'. The
terminating access switch is capable of merging calls in
response to a signal from the adjunct.
The ISDN link provides adjunct 68' with both the
called number (subscriber's PTN) and the calling number
(Automatic Number Identification number, or "ANI"). The
adjunct retrieves the subscriber's record and current status
information based on the PTN. From the subscriber's record
the adjunct also determines whether or not the subscriber is
provisioned to receive a Personal Identification Number
(PIN). If the subscriber is so provisioned, adjunct 68'
plays a standard prompting announcement to the caller after
which the PIN is collected from the caller by the reception
of up to 10 Dual Tone Multi Frequency (DTMF) digits (i.e.
Touch Toned signals from a Touch Tone telephone). In a
system using PINs, provision must be made for the case where
a caller can not enter a PIN because the caller is at a
rotary dial station and for the case where a caller does not
respond to the prompt. In these two cases, adjunct 68' may
allow for a time-out or an abbreviated dialing sequence
(e. g., #) to denote that no PIN is forthcoming. Regardless
of whether or not a PIN is collected, adjunct 68' proceeds
to determine if the subscriber 76' is busy with another call
to the subscriber's PTN. It stores this determination, and
then continues processing the call.
At this point, the adjunct plays an announcement
that the system will "search" for subscriber 76'. On a
- 20 -
S subscriber pre-provisioned basis, adjunct 68' may play an
announcement to the caller 40' as an inducement to remain on
the line while awaiting call completion. Meanwhile, the
adjunct retrieves the subscriber's pager code (known from
the PTN) and transmits the code along with the caller's ANI
(or PIN, if so provisioned) to a satellite station 70' via
a communication link 82'.
The satellite station broadcasts the pager code
and ANI (or PIN) to a paging transceiver 74' either through
a satellite 72' or through a communication coupling 85'.
When the satellite is used, the pager code and ANI (or PIN)
are transmitted to the satellite by way of a wireless link
84'. The satellite, in turn, broadcasts the pager code and
ANI (or PIN) to the transceiver by way of a wireless link
86'.
Communication coupling 85' is used when the two-
way pager is equipped for location registration. Under the
location
registration scheme, the two-way pager periodically sends
out a signal from which the satellite station determines the
region within which the mobile party is located. Once the
satellite station knows the mobile party's region, it need
only send the paging information to the transceiver
associated with that region. In this manner, the need for a
national broadcast to a11 transceivers via satellite is
obviated. Thus, when location registration is used satellite
station 70' may transmit the pager code and ANI (or PIN) to
transceiver 74' via communication coupling 85'. It will be
understood by those of ordinary skill in the art that
separate communication couplings from the satellite station
to each transceiver are not required. Rather, signals to a
transceiver that is not directly linked to the satellite
station may be relayed to that transceiver over a
transceiver network linked to the satellite station.
Regardless of whether satellite 72' or
~~ss4~~
- 21 -
communication coupling 85' is used, the transceiver 74'
broadcasts a paging signal that includes the pager code and
ANI (or PIN) to the subscriber's pager. Broadcasting from
transceiver 74' to pager 77' is represented by a wireless
link 88'. Upon receipt of the paging signal from the
transceiver, the subscriber is alerted to the call and
responds by sending a forwarding signal. The subscriber may
include any one of a number of possible responses in the
forwarding signal.
The subscriber may elect to forward the call to a
telephone station of the subscriber's choice, in which case,
the subscriber uses the two-way pager to transmit the number
of the desired telephone station to the transceiver.
Alternatively, the subscriber may forward the call to voice
mail, or some other treatment, in which case the subscriber
uses the pager to transmit a number associated with the
desired treatment.
The independence of the paging and communication paths
makes it possible for the subscriber to forward calls to the
subscriber's PTN even when the subscriber is busy with an
earlier call. This will be true regardless of whether the
earlier call was directed to the subscriber's PTN or
directly to the telephone station at which the subscriber
"picked up" the earlier call. Thus, in an illustrative
scenario, the subscriber forwards a first caller to a nearby
telephone station and picks up the call at that station.
Then, while talking to the first caller, the subscriber
forwards a second caller to a secretary, forwards a third
caller to voice mail, and so on. The subsequent calls may be
the forwarded without interruption of the first call and
without the first caller becoming aware of them.
In addition to transmitting call forwarding
instructions, the subscriber may transmit special call
handling instructions, such as putting a caller on hold,
switching between callers, creating a conference call, and
~~~~~J~~
- 22 -
redirecting a previously forwarded call. In a one possible
embodiment, these special instructions are implemented by
assigning them a number which the subscriber sends to the
transceiver in the same way that a forwarding number is
sent. Thus, in an example of switching between callers, a
busy subscriber who receives a second call may send the
number 999 to the transceiver indicating that the first
caller should be put on hold and the second caller forwarded
to the subscriber's present telephone station. In an example ,
of redirecting a previously forwarded call, a busy
subscriber who has forwarded a subsequent call to voice mail
but later becomes free to take the subsequent call, may
interrupt the forwarding of the subsequent call by sending
the number 000 to the transceiver before the forwarded
caller disconnects, the 000 indicating that the forwarded
call should be released from voice mail and forwarded to the
subscriber. Regardless of the call handling
treatment chosen by the subscriber, the two-way pager
transmits the forwarding signal to transceiver 74', as
represented by wireless link 89'. The transceiver relays the
two-way pager's transmissions to satellite station 72',
either through satellite 72' via wireless links 86' and 84',
or through communication link 85'. The satellite station
then relays the subscriber's instructions to the adjunct via
communication link 82', and the adjunct responds
accordingly.
To forward the call to a called party telephone 52',
the adjunct initiates a second call. The second call is
routed to a third access switch 48' via a trunk line 60'
(like switches 44' and 46', switch 48' may be a digital
switch or a 4E switch). The third access switch then routes
the second call to a local end office 50' based on the
forwarding number provided by the subscriber, the forwarding
number being the number of called party telephone 52', to
which the original call will be forwarded. The local end
- 23 -
office couples the second call to the called party telephone
via a telephone line 64'.
Upon completion of the second call, the call from
the caller to the PTN (on hold at the adjunct) and the
second call are either bridged together within adjunct 68'
(in which case the adjunct remains with the call), or merged
at switch 46' (in which case the adjunct drops from the
call). If the calls are bridged, the adjunct may implement
the features of putting a caller on hold, switching between
callers, creating a conference call, and interrupting a
previously forwarded call. Whereas, if the calls are merged,
switch 46' may implement these features under direction from
the adjunct.
During the interval of time between the dialing of
the subscriber's PTN to initiate a call and the final
disposition of that call (the call set up time), an
announcement may be played to the caller as an inducement to
stay on the line while the call is processed.
FIGS 3, 4A and 4B will be referenced in the
following discussion of the procedure for updating the
forwarding number in accordance with the call by call mode.
The first step the subscriber takes to update the
forwarding number is to depress menu key 104 on pager l00
(step 202). The word "update" will appear in display l02.
The subscriber then depresses select key l06 to select
"update" (step 204) . The word "update" will flash in the
display to indicate that the subscriber may enter the update
number (step 206). The subscriber may now input the
forwarding number via keypad l08 followed by the # key to
indicate the end of input (step 208) . To enter a special
call handling instruction, such as a conference call
instruction, a number associated with that instruction would
be input rather than a forwarding number (step 208). A
subscriber who does not want to change the forwarding number
and does not want to input a special instruction number may
21e433
- 24 -
simply depress the # key without keying in a number.
Moreover, in one possible embodiment, the pager is
equipped with the ability to store forwarding numbers so
that abbreviated key sequences may be used to change the
forwarding number. For example, the subscriber's office
telephone number may be stored in the pager's memory at a
first location and the subscriber's home telephone number
may be stored in the pager's memory at a second location.
Thereafter, when the subscriber wants to change the
forwarding number to the office number, the subscriber
simply keys in a 1 followed by the # sign. Similarly, when
the subscriber wants to change the forwarding number to the
home number, the subscriber simply keys in a 2 followed by
the # sign.
In any case, after receiving a # input, the
pager's mode indicator will flash (step 2l0). At this point,
the subscriber must select the desired mode (step 212) (To
implement call by call forwarding the subscriber would
select call by call mode). The pager determines if the
desired mode is the current mode (step 2l4/222). If the
subscriber desires the call by call mode and the current
mode is not the call by call mode, then before the flashing
mode indicator goes steady, the subscriber depresses select
key 106 to change to call by call mode (step 224). If the
current mode is the call by call mode, the subscriber allows
a period of time to pass, after which the flashing mode
indicator will go steady; or, in the alternative, the
subscriber may depress the # key to curtail timing and
retain the current mode (step 226). After the mode has been
selected, the pager signals the transceiver 112, sending the
pager code, updated forwarding number, and a call by call
mode indicator (step 228).
Following reception of the pager's transmission,
represented by wireless link 111, transceiver 112 relays the
pager code, updated forwarding number, and mode indicator to
- 25 -
satellite station 116 either through wireless link l13,
satellite 114, and wireless link 1l5; or, when location
registration is used, through communication link 117 (step
230). Finally, the satellite station relays the forwarding
number to the adjunct where it is used to forward an
incoming call (step 232). At this point the update is
complete (step 234).
FIGS. 9A and 9B show, in flowchart form, the steps
taken in forwarding calls on a call by call basis. In the
following discussion of FIGS 9A and 9B references will be
made to FIG 8.
The call by call procedure is invoked when caller
40' dials the subscriber's PTN (step 302). The call is
routed to originating access switch 44', or "OAS", (step
304) and the OAS queries NCP 66' (step 306). The NCP returns
an Adjunct Routing Number (ARN) to the OAS, causing the call
to be routed to adjunct 68' via terminating access switch
46', or "TAS A", (step 308). The terminating access switch
passes the calling number, determined through ANI, and the
called PTN to the adjunct (step 3l0). The adjunct then
retrieves the subscriber's record based on the dialed PTN
(step 312) and determines if the subscriber has provisioned
for a PIN to be collected from the caller (step 3l4).
If a PIN has been provisioned for, adjunct 68'
plays a prompt and collects DTMF digits (step 3l6). If a PIN
has not been provisioned for, the procedure skips to step
318 which is to determine if the subscriber is busy (i.e.,
if a call to the subscriber via the adjunct is in progress).
If the subscriber is busy, the next step is to
check if the subscriber has Call Waiting (step 320). If the
subscriber does not have Call Waiting, the call is routed to
final treatment, such as Voice Mail (step 402). If the
subscriber does have Call Waiting, the subscriber is paged,
the paging signal including the pager code, calling number
(or PIN), and a call identifier (step 404). If the
_ ~16~~'~~
- 26 -
subscriber does not respond to the page within some
predetermined time after the page is sent (step 405), the
caller is "timed out" and the call is routed to final
treatment (step 406). The subscriber may respond within the
allotted time by initiating transmission of a forwarding (or
"reach") number, or a conference call instruction (step
428), and processing of the call continues in accordance
with the steps following step 428.
If it is determined in step 318 that the
subscriber is not busy, adjunct 68' determines whether or
not the subscriber is taking calls (step 322). If calls are
not being accepted, the call is forwarded to final treatment
(step 408). Otherwise, the adjunct retrieves the
subscriber's pager code (step 4l0) and transmits the pager
code, calling number (or PIN), and call identifier to the
paging service (step 4l2). The paging service then
broadcasts the information (step 414) to pager 77' which
alerts the subscriber and displays the calling number (or
PIN) and the call identifier (step 416). At this point, the
subscriber may accept or reject the call (step 4l8).
There are two ways by which the subscriber may
reject the call. The subscriber may do nothing, in which
case the caller will be timed out (step 420) and the adjunct
will route the call to final treatment (step 426). Or, the
subscriber may send a rejection signal (a special
instruction) to the paging service (step 422), in which case
the paging service will relay the rejection signal to the
adjunct (step 424) and the adjunct will cause the call to be
routed to final treatment (step 426). If the subscriber
elects to take the call, the subscriber initiates
transmission of a reach number by way of two-way pager 77'
(step 428).
Thus, the subscriber may transmit either a reach
number or a conference call instruction at step 428 of the
process. Upon receipt of a number, the paging service
2e5433
- 27 -
transmits the number and the call identification to the
adjunct (step 430). Next, the adjunct checks whether or not
there is another presently active call to the subscriber
(step 432).
In the event there is a presently active call, the
adjunct checks to see if a conference call instruction was
received (step 435). If a conference call instruction was
not received, the adjunct puts the active call on hold (step
434) and bridges/merges the new call to the subscriber (step ,
436). If a conference call instruction was received, the
adjunct bridges/merges the new call to both the subscriber
and the original caller (step 437).
In the event there is not another presently active
call, step 434 is skipped and the adjunct bridges/merges
(step 436) the new call to the subscriber immediately
following step 432. The procedure is complete upon
bridging/merging of the call (step 438).
Referring back to FIG. 6, adjunct 73, switch 47,
communication couplings 45,49,75, and wireless link 87
function in the same manner as their counterpart elements in
FIG. 8 (viz. adjunct 68', switch 46', communication
couplings 48', 80', 82', and wireless link 88'). When the
call reaches switch 44, switch 44 queries NCP 66 which, in
turn, queries CRP 68 for instructions. If the subscriber has
only subscribed to registration type service the call may be
handled according to the procedures set forth in connection
with FIG. 5. However, if the subscriber has subscribed to
features available only through call by call type service,
such as the conference call feature, the CRP directs switch
44 to route the call to adjunct 73. Once the call has been
redirected to the adjunct, the adjunct may handle the call
according to the procedures set forth in connection with
FIGs 9A and 9B . Thus, both registration and call by call
type service may be offered through the configuration of
FIG. 6.
21~~4~~
- 28 -
As an added feature of the preferred embodiment of
FIG. 6, adjunct 73 is coupled to CRP 68 via communication
coupling 71. Accordingly, when the CRP directs a call to the
adjunct, the adjunct can query the CRP for the subscriber's
record and current status information. In this manner the
CRP may act as the database from which the adjunct retrieves
the paging information necessary to implement call by call
forwarding.
